Runte Christoph, Tawana Djafar, Dirksen Dieter, Runte Bettina, Lamprecht-Dinnesen Antoinette, Bollmann Friedhelm, Seifert Eberhard, Danesh Gholamreza
Department of Prosthodontics, University of Muenster, Waldeyer Strasse 30, D-48149 Muenster, Germany.
Int J Prosthodont. 2002 May-Jun;15(3):254-8.
The aim of the study was to measure the influence of the maxillary central incisors free from adaptation phenomena using spectral analysis.
The maxillary dentures of 18 subjects were duplicated. The central incisors were fixed in a pivoting appliance so that their position could be changed from labial to palatal direction. A mechanical push/pull cable enabled the incisor section to be handled extraorally. Connected to the control was a sound generator producing a sinus wave whose frequency was related to the central incisor angulation. This acoustic signal was recorded on one channel of a digital tape recorder. After calibration of the unit, the denture duplicate was inserted into the subject's mouth, and the signal of the /s/ sounds subsequently produced by the subject was recorded on the second channel during alteration of the inclination angle simultaneously with the generator signal. Spectral analysis was performed using a Kay Speech-Lab 4300B.
Labial displacement in particular produced significant changes in spectral characteristics, with the lower boundary frequency of the /s/ sound being raised and the upper boundary frequency being reduced.
Maxillary incisor position influences /s/ sound production. Displacement of the maxillary incisors must be considered a cause of immediate changes in /s/ sound distortion. Therefore, denture teeth should be placed in the original tooth position as accurately as possible. Our results also indicate that neuromuscular reactions are more important for initial speech sound distortions than are aerodynamic changes in the anterior speech sound-producing areas.
本研究旨在通过频谱分析测量不受适应现象影响的上颌中切牙的影响。
复制18名受试者的上颌义齿。将中切牙固定在一个枢轴装置中，以便其位置可以从唇侧方向改变为腭侧方向。一根机械推/拉电缆使切牙部分能够在口外操作。与控制器相连的是一个产生正弦波的发声器，其频率与中切牙的角度有关。该声学信号记录在数字磁带录音机的一个通道上。在对该装置进行校准后，将义齿复制品插入受试者口中，并在改变倾斜角度的同时，将受试者随后发出的/s/音信号与发声器信号一起记录在第二个通道上。使用Kay Speech-Lab 4300B进行频谱分析。
特别是唇侧移位会使频谱特征产生显著变化，/s/音的下限频率升高，上限频率降低。
上颌切牙位置会影响/s/音的产生。上颌切牙的移位必须被视为/s/音立即失真变化的一个原因。因此，义齿牙齿应尽可能准确地放置在原来的牙齿位置。我们的结果还表明，对于初始语音失真，神经肌肉反应比前语音产生区域的空气动力学变化更重要。
